Help with the "READ" and "WRITE" command, using RFID tags.

Element

Hello,

I am new to the BS2 code, and i am also new to the RFID tags, and reader. I have stuck to BS1 up until now, and I am asking for some help. I have tried everything, and i have not got this to work , i have gotten up to making the first tag, but after that, i don't know what to do, because i want to compare the second tag to the first.

I am using BS2, and the Parallax RFID reader,tags, and their program.

What i want to do is make a navigation program using the RFID tags, and the BS2 program.

So when the robot is told to go to a room, it will start moving until the RFID reader finds the first tag, I want to write that tag number into the EEPROM. So when the RFID reader finds the second tag, I want it to read the first tag from that stored location in the EEPROM. Then from there, i will write in the program a sub-program using the code "IF THEN".

So, my question is after the first tag has been found, how do use the codes "WRITE" and "READ" for this to work?

Thanks,
Element

Chris Savage

Element,

You can use the RFID_Basic code to get an idea how to read a tag. Storing the data using WRITE would require a loop and 10 bytes of memory to store the data. Reading the data will be similar. It would need to be done with a loop. Are you trying to map tag locations or just log them?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support

LSB

I think we've spoken of this before, If i recall the idea is to use the cards as waypoints to control navigation. The robot could recognize direction and distance from the order the cards are encountered. I think the whole problem is exponitially simpler if the card IDs are reduced in lenth. If, perhaps, it were possible to use a lookup function to reduce (or 'alais') the card ID to a BYTE size variable... this would fit nicely into an array and become Card(ID)=Order encountered, or Card(ORDER)=ID or...
I think the idea is very clever and was wondering if the TSL230 was sensitive/ consistant enough to differentiate 256 shades of gray...

Bruce Bates

Gents -

I suspect the problem that you may eventually have in using RF ID tags for waypoints may be that you have to get quite close to them before they can be read. If they were on a pre-determined route (as in a walled maze) you could tell where you were in the maze, but only because the area is bounded. In an unbounded area, how can you be sure to get close enough to an RF ID tag which may or may not be there?

Regards,

Bruce Bates

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
<!--StartFragment -->

LSB

Bruce,
The post I am referring to was in regard to navigating a maze. Also, RFID may not be the only waypoints.